I am glad that different opinions are being expressed here. Dr Luning for example is a noted skeptic and the balance provided by different views provides perspective. It also demonstrates, that contrary to current dogma, the debate is far from over. There is no consensus on the relative weights of CO2-driven climate change and natural variability. Further, science has never progressed by following a consensus. This is true of Newton’s view on gravity, Einstein’s theory of relativity, or plate tectonics. In the last case, in the 1950′s the consensus view was that continents are fixed, and the fixists even had Einstein endorse their view in 1955 just before his death. Of course this was turned over by plate tectonic theory and its corroboration via global positioning system (GPS) data.

This is intended as constructive criticism. I was disappointed by the Warren questionnaire. To me, the questions were too simplistic. Almost all skeptics as well as warmists agree that CO2 is a greenhouse gas. Almost all agree that mankind is having some effect. But neither of these are the true issue. The real issue is the relative weight of CO2-driven climate change versus natural variability. Furthermore, the questionnaire went on to ask questions about policy for dealing with climate change. Obviously, such questions are based on the assumption that a) the scale of CO2-driven change is a problem, b) that we are capable of effecting change, and c) that even if a) and b) are true, it is economically worthwhile to attempt change now. For these reasons, this year I did not complete the questionnaire.

The IPCC has convinced politicians and the Main Stream Media that there is a problem. Meanwhile, the IPCC in its report in October 2013 for example shows a decreasing trend in Arctic sea ice over the last 30 years but fails to show the increasing trend in Antarctica (in direct contrast to their models). Note also that this month Antarctic sea ice reached the highest level ever recorded in the satellite era. The IPCC shows decreasing Northern Hemisphere snow cover for Spring, but fail to show increasing snow cover in Autumn and Winter.

100% of the IPCC endorsed models show increasing temperatures extending from the 1980′s through the 2010′s and 2020′s whereas reality shows global temperatures have stood still for between 12 and 17.7 years (depending on which data set is used). This implies that the so-called “97%” consensus is irrelevant given that 100% of the climate models are wrong. The USHN temperature data-set only shows increasing temperature trends once adjustments have been made. The raw data show a different picture. These adjustments are on-going. Surely, the real effect of time of observation (TOBS), infilling and gridding needs rigourous review.

Tide guage data show sealevels rising at 1.6 mm / year whereas the GIA adjustment to satellite data pushes that rate of increase to 3.2 mm / year. The tide-gauge data shows no acceleration in the rate, implying that the natural rate, on-going since 1750, is continuing as normal. An acceleration would be required to imply an anthropogenic effect.

The emphasis on recent times has taken away the perspective provided by historic and geological scale change. Isotopic and geochemical data show CO2, temperature, and sealevel have been higher in the past. Over the last 1 million years the planet has, all on its own, repeatedly switched from ice age to interglacial, a change that implies between 8 and 10 Degree C change. Meanwhile, the temperature change being discussed in terms of “global warming is less than 1 Degree C. In other words, a change that is less than 10% of the known natural variability is being ascribed to CAGW. More worryingly, changes to our energy mix and energy strategy have already been enacted on this basis.

Regarding policy, the above shows that the case for CAGW is far from secure. On the contrary, more and more evidence (as noted above) suggests that natural variabilty trumps CAGW (otherwise there would be no standstill in global temperatures. As they say, if you can’t explain the pause, you don’t know the cause). Even then studies have shown that CAGW may cause a reduction in future GDP of 2%. Meanwhile the policy-driven cure will cost 4% of GDP. It is clearly not a good idea to spend more on the cure than the predicted negative impact.